Abstract: Seismic Modeling and Geostatistical Lithofacies Simulation of an Outcrop Case Study: A Step Towards the Integration of Seismic Data in Reservoir Simulations

Remi Eschard, Aline Bourgeois, Pierre Yves Dequirez, Vincent Richard

A synthetic section interpreted in lithofacies has been constructed from the study a large outcrop in order to test on a "true" geological model different methods and tools in the field of the seismic processing and geostatistical reservoir modeling.

The large outcrops of the Campanian deltaic series of Colorado were studied to build a 6 km long and 350 m thick 2D section. The section was interpreted in sedimentary facies then digitized in order to compile a high-resolution grid for both geophysical and geostatistical simulations. Eleven facies where then determined in offshore, shore face, foreshore and coastal-plain environments.

Rock properties such as P - wave, S - wave velocity and density were assigned to each cells of the model, and the target was buried. A fully elastic seismic modeling was then computed, and data post- processing included wavelet extraction, stratigraphic modeling and stratigraphic inversion. Pre - stack and post - stack inversions have also been performed. In the pre - stack inversion, the variation of the reflection coefficient amplitudes versus offset is taken into account, and, as consequence, resolution is very much improved.

A geostatistical analysis was also performed on the same data - set, proportion curves of lithofacies and variograms were computed and different stochastic approaches were tested.

The next step will be the computation of geostatistical parameters on seismic data in order to better constrain stochastic reservoir simulations with seismic data.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France